Divine by Blood (Divine #3)

Conceived in a lie and trapped in a tree throughout her gestation, Morrigan's birth was truly magical. After that start, she spent the next eighteen years raised as a normal girl in Oklahoma.

Long Synopsis:

Conceived in a lie and trapped in a tree throughout her gestation, Morrigan's birth was truly magical. After that start, she spent the next eighteen years raised as a normal girl in Oklahoma. Upon discovering the truth of her heritage, her rage and grief take on a power of their own, carrying her back to the world of Partholon. Yet, instead of being respected as the daughter of the Goddess Incarnate, Morrigan feels like a shunned outsider. In her desperation to belong to Partholon, she confronts forces she can't fully understand or control. And soon a strange darkness draws closer. . . .